Block #319,010

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 12/18/2013, 6:09:23 PM · Difficulty 10.1630 · 6,476,637 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
d2fb10b81eb7220fb842eb26dadc8568b3c5bf827b4c25ecb392a352790f8c50

Height

#319,010

Difficulty

10.163014

Transactions

1

Size

1.05 KB

Version

2

Bits

0a29bb41

Nonce

86,878

Timestamp

12/18/2013, 6:09:23 PM

Confirmations

6,476,637

Merkle Root

ca70e174e6cbc16ea8407d3dc11b4817ba3622b37687522268e88ab9dd31b741
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

4.355 × 10¹⁰⁰(101-digit number)
43553988378170062047…32285361935935385599
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
4.355 × 10¹⁰⁰(101-digit number)
43553988378170062047…32285361935935385599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
8.710 × 10¹⁰⁰(101-digit number)
87107976756340124094…64570723871870771199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.742 × 10¹⁰¹(102-digit number)
17421595351268024818…29141447743741542399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.484 × 10¹⁰¹(102-digit number)
34843190702536049637…58282895487483084799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
6.968 × 10¹⁰¹(102-digit number)
69686381405072099275…16565790974966169599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.393 × 10¹⁰²(103-digit number)
13937276281014419855…33131581949932339199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.787 × 10¹⁰²(103-digit number)
27874552562028839710…66263163899864678399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
5.574 × 10¹⁰²(103-digit number)
55749105124057679420…32526327799729356799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.114 × 10¹⁰³(104-digit number)
11149821024811535884…65052655599458713599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.229 × 10¹⁰³(104-digit number)
22299642049623071768…30105311198917427199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
4.459 × 10¹⁰³(104-digit number)
44599284099246143536…60210622397834854399
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

★★★☆☆
Rarity
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,609,246 XPM·at block #6,795,646 · updates every 60s
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